Needle control device for circular knitting machines



M. B. BAKER June 18, 1963 NEEDLE CONTROL DEVICE FOR CiRCULAR KNITTING MACHINES Filed Oct. 28. 1960 INVENTOR. Mmavm B. BAKE-E.

' ATTORNEYS Uted States This invention relates to a needle control device for maintaining the needles of a circular knitting machine in properly spaced apart and circular alinement and the present invention is of particular value in line gauge circular machines of the type adapted to knit sheer ladies hosiery.

In fine gauge circular hosiery knitting machines, a large number of needles are positioned for vertical movement in slots in the outer periphery of the needle cylinder. The needles are necessarily thin and flexible cylinthe slots in the needle cylinder are somewhat wider than the needle shank. The needles are maintained in the slots in the needle cylinder by a plurality of circular spring bands which are carried in an annular groove cut in the upper portion of the needle cylinder. The spring bands engage the outer edges of the shanks of the needles to force the needles inwardly so that their inner edges are maintained against the bottoms of the slots in the needle cylinder. As is well known, the shank of the needles is reduced or narrowed beneath the latch and when the needles are successively lowered to stitch drawing position, a narrow portion of the needle shank is positioned adjacent the spring bands and the narrow portion of the lowered needles are not engaged by the spring bands because the wider portions of the shanks of needles at opposite sides of the lowered needles hold the spring hands outsides of the lowered needles hold the spring bands outwardly and out of engagement with the narrow portions of the shanks of the lowered needles. Thus, at the most critical time, when the needles are lowered to stitch drawing position, the spring bands do not press inwardly against the shanks of the lowered needles and therefore the inner edges of these lowered needles are not maintained firmly against the bottoms of the slots in the needle cylinder. Since the needles are not held firmly against the bottoms of the slots as they are lowered to stitch forming position, they are not maintained in proper alinement and may form longer or shorter than normal stitches and thereby cause objectionable streaks in the knit fabric.

With the foregoing in mind, it is the primary object of the present invention to provide needle control means which is adapted to engage the narrowed shank portions of the needles and press the back edges of the needles into firm engagement with the bottoms of the slots in the needle cylinder and thereby maintain the needles in proper alinement as they are moved downwardly to stitch drawing or forming position.

It is another object of the present invention to provide a needle control device of the type described which can be easily attached to existing circular hosiery knitting machines without requiring any substantial modification of the existing knitting machine.

It is a more specific object of the present invention to provide a needle control means for maintaining the needles of a fine gauge circular knitting machine in proper alinement during the stitch forming operation which includes a rotatable circular element, the peripheral edge of which is adapted to engage and press inwardly against the outer edges of the shanks of the needles as the needles are lowered to stitch drawing position to maintain the inner edges of the needles firmly against the bottoms of the slots in the needle cylinder and thereby maintain the needles in proper alinement.

It is another object of the present invention to provide ice a needle control means of the type set forth above in which the peripheral edge of the rotatable circular element is serrated to provide a plurality of needle shank receiving notches adapted to receive the outer edges of the needle shanks therein as the needles are lowered to stitch drawing position to thereby maintain the needles in uniformly spaced apart relationship.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which-- FIGURE 1 is a fragmentary side elevation of the upper portion of a conventional knitting machine having the needle control device of the present invention applied thereto; 7

FIGURE 2 is an enlarged fragmentary sectional plan view taken substantially along the lines 2-2 of FIG- URE 1;

FIGURE 3 is a greatly enlarged fragmentary view of a portion of the needle control device and showing the peripheral edge thereof in engagement with the narrow portion engaging the shanks of several of the needles carried in the needle cylinder;

FIGURE 4 is an enlarged vertical sectional view taken through the needle control device, showing the sinker cap and needle cylinder in section and illustrating the manner in which the peripheral edge of the needle control device engages the stepped outer edge of the needles;

FIGURE 5 is a developed schematic view of the stitch drawing cams, illustrating the path of travel of the needles as they are lowered to stitch drawing position and showing the relative location of the needle control device above the stitch drawing cam.

Referring to the drawings, it will be noted that a Scott 8: Williams type circular knitting machine is shown, however, it is to be understood that the needle control device of the present invention may also be utilized with other types of circular machines. The circular knitting machine includes an upper bed plate It) and a needle cylinder 11 which is mounted for driven rotation of the bed plate 10. The needle cylinder T1 is provided with radially spaced apart needle slots 12 (FIGURES 3 and 4), each of which supports a latch needle N for vertical sliding movement therein. The needle N has an outwardly extending operating butt 15 at its lower end, a hook T6 and a latch 17 at its upper end and a shank 18 intermediate the ends thereof (FIGURE 4). The rear or inner edge of the shank 18 is straight and engages the bottom of the slot 12 in the needle cylinder 11 while the front or outer edge of the shank 18 is stepped and progressively narrowed toward the upper end.

The upper portion of the needle cylinder 11 is provided with an annular groove 14 (FIGURES 3 and 4) which is positioned immediately beneath a sinker head, broadly indicated at 19. It will be noted in FIGURE 3 that the annular groove 14 is cut deep enough that the slots 12 are very shallow adjacent the groove 14. In fact, in the area of the annular groove 14, the slots 12 are not much more than immissions in the needle cylinder Ill. The annular groove 14 is usually provided with four spring bands 2%), however, in the present instance one of the spring bands 2% has been removed to provide room for the needle control device of the present invention, to be presently described.

The sinker head 19 includes a sinker cap 21 and a sinker bed 22 which is suitably secured to the upper end of the needle cylinder 11. The sinker bed 22 is provided with radially extending grooves in which sinkers S are mounted for radial sliding movement. The radial position of the sinkers S is controlled by suitable cams, not shown, in the sinker cap 21 to control the operation of the sinkers in a conventional manner.

Referring to FIGURE 5, it will be noted that the knitting machine is provided with the usual stitch earns 23 and 24, a landing cam 25, a center cam 26 and end earns 27 and 28. When the machine is in rotary knitting, the needles N travel from right to left in FIGURE and they are raised to stitch shedding level by the cam 23, lowered by cam 25 to pick up yarn Y from yarn feed finger St) at the throat opening in latch ring 31 and then lowered by cam 24 to form knit stitches. The needles N reach their lowest point as their butts pass beneath the lower point 32 of the stitch cam 24. As the needles continue past the stitch cam 24, they are raised by the end cam 28 and the sinkers S cooperate with the needles to shed the stitch loops fro-m the hooks 16 of the needles N, in the usual manner.

The foregoing parts are conventional parts of a circular hosiery knitting machine and it is with this general type of machine that the present invention is shown. In its preferred form, the needle control device of the present invention includes a rotatable wheel 35 which may be formed of metal, such as brass, or of synthetic material, such as nylon. The wheel 35 is preferably provided with an antifriction bearing 36 which is suitably secured, as at 37, on the inner end of an arm 4%. The outer end of the arm 40 is pivotally secured as at 41 (FIGURE 2) on the upper end of a support post 4-2 (FIGURE 1). The lower end of the support post 42; is supported on a plate 43 which in turn is secured on the upper bed plate It).

The wheel 35 and arm 40 are normally urged in a clockwise direction in FIGURE 2 by a tension spring 45, one end of which is connected intermediate the ends of the arm 40 and the other end of which is connected to a spring perch 46. The spring perch 46 may be attached in any suitable position on the machine and is shown on the usual sinker head hold-down arm 59. Thus, the tension spring 45 resiliently urges the wheel 35 inwardly toward the needle cylinder 11. As shown in FIGURE 4, the peripheral edge of the wheel 35 is positioned in the annular groove 14 of the needle cylinder 11 and between the lowermost and the two upper spring bands 20.

Referring to FIGURE 3, the shanks 18 of the needles N are shown in section to clearly illustrate that a narrow portion of the needle shank is positioned adjacent the spring bands as the needles N are lowered by the stitch cam 24. As shown in FIGURE 3, the spring bands 20 are not engaging the outer edges of the shanks 18 of the lowered needles N while they are engaging the shanks 13 of the needles adjacent opposite sides of the lowered needles N. Thus, the spring bands 24? do not engage and hold the lowered needles N inwardly against the bottoms of the slots 12 at this critical time when the needles are lowered to stitch drawing position.

As shown in FIGURE 3, the peripheral edge of the wheel 35 is being resiliently urged against the outer edges of the shanks 18 of a plurality of the lowered needles N adjacent the lowermost point 32 of the stitch cam 24 to firmly press their inner edges against the bottoms of their respective slots 12 and thereby hold the needles in proper alinement at this critical time when the needles are lowered to stitch drawing position. Because the slots 12 in the needle cylinder 11 are wider than the thickness of the shanks 18 of the needles N, it is also desirable to stabilize the needles and prevent sidewise movement thereof during the critical stitch drawing action. In order to provide uniform spacing of the needles and to prevent sidewise movement, it is preferred that the peripheral edge of the wheel 35 be serrated to hold the needles in proper spaced apart relationship. The peripheral edge of the wheel 35 is provided with outwardly projecting equally spaced apart teeth 55 which define needle shank engaging notches 56 therebetween. As shown in FIGURE 3, the notches 56 are simultaneously engaging and pressing inwardly against the outer edges of the shanks of three needles and the teeth projecting inwardly therebetween stabilize and prevent sidewise movement of the shanks of the needles. Of course, by increasing the diameter of the wheel 35, the outer peripheral edge would engage a greater number of the shanks of the needles and by decreasing the diameter of the wheel 35, the outer peripheral edge would engage a lesser number of the shanks of the needles.

In order to change the amount of inward pressure exerted against the needle shanks 18 by the peripheral edge of the wheel 35, it is merely necessary to vary the tension of the spring 45. If desired, the inward movement of the wheel 35 may be limited by adjustment of an adjustable stop screw 6;) (FIGURE 2). One end of the screw 68 is positioned in alinement with the arm 4%) and the medial portion threadably penetrates the upper end of a support bracket 61. The lower end of the support bracket 61 is suitably secured on the support post 42.

It is preferred that the teeth 55 and notches 56 on the peripheral edge of the wheel be machined therein in proper spaced relationship in accordance with the spacing of the needles N in the needle cylinder 11. However, the wheel 35 may be molded of a suitable plastic or nylon material and the serrated edge formed during the molding process. It is also possible to form the peripheral edge of the wheel 35 of a resilient material which will deform when pressed against the shanks of the needles and extend inwardly therebetween to the desired extent.

The wheel 35 is mounted to rotate with the needle cylinder 11, however, it is to be understood that a nonrotating wheel having a smooth peripheral edge may be used to press inwardly against and hold the needle shanks 18 firmly seated in the slots 12, if desired. Also, a cam member having a curved inner face could be used in place of the wheel 35. In this case, the cam member would be positioned in the same relative vertical and radial position as the wheel 35 and its inner face would be curved to press inwardly against the shanks of the lowered needles. A cam of this type would not provide uniform sidewise spacing of the needles, however, it would hold the needles inwardly against the bottoms of the needle slots 12 and maintain the needles in uniform radial alinement during the formation of stitches thereby.

In a circular knitting machine having the needle control device of the present invention applied thereto, the spring bands 26 act as a main needle engaging means to normally maintain the majority of the needles inwardly against the bottoms of the slots 12 in the needle cylinder 11 while the wheel 35 acts as an auxiliary needle engaging means to maintain a few of the needles inwardly against the bottoms of the slots 12 in the needle cylinder Ill.

The needle control device of the present invention thus provides means engagcable with the shank portion of the needles to press the needles inwardly and maintain the same in firm engagement against the bottoms of the needle slots as the needles are lowered to stitch drawing position. In the preferred form of needle control device, means is also provided to maintain the needles in proper spaced apart alinement as the needles are lowered to stitch drawing position. Also, the present needle control device may be easily applied to conventional circular knitting machines without any substantial modification of the knitting machine. In circular knitting machines having more than one knitting station, a needle control device of the present invention would be provided at each knitting station.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. In a circular knitting machine having a rotatable needle cylinder with needle receiving needle slots therein, independently operable needles positioned for vertical movement in the slots of said cylinder, stitch cam means positioned adjacent said cylinder and adapted to lower said needles to stitch forming position, and radially movable sinkers positioned at the upper end of said cylinder and cooperating with said needles to successively form knit stitch loops, the combination therewith of a needle engaging wheel positioned adjacent the outer periphery of said cylinder and below said sinkers, and the peripheral edge of said wheel being positioned above said stitch cam means to press a few of the needles inwardly into firm engagement with the bottoms of the slots in said needle cylinder as the needles are lowered by said stitch cam means.

2. In a structure according to claim 1 including resilient means normally urging the peripheral edge of said wheel against said few needles.

3. In a structure according to claim 2 including adjustable stop means for limiting the innermost position of the peripheral edge of said wheel.

4. In a circular knitting machine having a rotatable needle cylinder with needle receiving needle slots therein, independently operable needles positioned for vertical movement in the slots of said cylinder, stitch cam means positioned adjacent said cylinder and adapted to lower said needles to stitch forming position, and radially movable sinkers positioned at the upper end of said cylinder and cooperating with said needles to successively form knit stitch loops; the combination therewith of a rotatable needle engaging wheel positioned adjacent the outer periphery of said cylinder and below said sinkers, the peripheral edge of said wheel being serrated to define outwardly projecting teeth having needle engaging notches therebetween, the needle engaging notches being positioned above said stitch cam means to press a few of the needles inwardly into firm engagement with the bottoms of the slots in said needle cylinder as the needles are lowered by said stitch cam means, and said outwardly projecting teeth extending inwardly between said few needles to prevent sidewise movement of said few needles in the slots of said needle cylinder.

5. In a structure according to claim 4 including resilient means normally urging the needle engaging notches of said wheel against said few needles.

6. In a structure according to claim 5 including adjustable stop means for limiting the amount of inward movement of the needle engaging notches of said wheel.

7. In a circular knitting machine having a frame, a bed plate supported by said frame, a rotatable needle cylinder supported by said bed plate and having needle receiving needle slots therein, independently operable needless positioned for vertical movement in the slots of said cylinder, stitch cam means positioned adjacent said cylinder and adapted to lower said needles to stitch forming position, and radially movable sinkers positioned at the upper end of said cylinder and cooperating with said needles to successively form knit stitch loops; the combination therewith of needle engaging means positioned adjacent the outer periphery of said cylinder, said needle engaging means comprising a support post mounted on said bed plate, an arm pivotally supported at one end on said support post, a needle engaging wheel rotatably mounted on the other end of said support arm, and the periphenal edge of said wheel positioned below said sinkers and above said stitch cam means to engage and press a plurality of said needles inwardly into firm engagement with the bot-toms of the slots in said needle cylinder as the needles are lowered by said stitch cam means.

8. In a structure according to claim 7 wherein the peripheral edge of said wheel is serrated to define outwardly projecting teeth having needle engaging notches therebetween, the needle engaging notches engaging said few needles, said outwardly projecting teeth extending inwardly between said few needles to prevent sidewise movement of said few needles in the slots of said needle cylinder, and resilient means connected to said support arm and normally urging the needle engaging notches of said wheel against said few needles.

9. In a structure according to claim 8 including adjustable stop means carried by said support post and engageable with said support arm to limit the amount of inward movement of the needle engaging notches of said wheel.

References Cited in the file of this patent UNITED STATES PATENTS 595,698 Cummings Dec. 21, 1897 1,027,034 Crane May 21, 1912 1,066,367 Berry July 1, 1913 2,066,440 Winter et a1 Jan. 5, 1937 2,596,535 Curtis May 13, 1952 

1. IN A CIRCULAR KNITTING MACHINE HAVING A ROTATABLE NEEDLE CYLINDER WITH NEEDLE RECEIVING NEEDLE SLOTS THEREIN, INDEPENDENTLY OPERABLE NEEDLES POSITIONED FOR VERTICAL MOVEMENT IN THE SLOTS OF SAID CYLINDER, STITCH CAM MEANS POSITIONED ADJACENT SAID CYLINDER AND ADAPTED TO LOWER SAID NEEDLES TO STITCH FORMING POSITION, AND RADIALLY MOVABLE SINKERS POSITIONED AT THE UPPER END OF SAID CYLINDER AND COOPERATING WITH SAID NEEDLES TO SUCCESSIVELY FORM KNIT STITCH LOOPS, THE COMBINATION THEREWITH OF A NEEDLE ENGAGING WHEEL POSITIONED ADJACENT THE OUTER PERIPHERY OF SAID CYLINDER AND BELOW SAID SINKERS, AND THE PERIPHERAL EDGE OF SAID WHEEL BEING POSITIONED ABOVE SAID STITCH CAM MEANS TO PRESS A FEW OF THE NEEDLES INWARDLY INTO FIRM ENGAGEMENT WITH THE BOTTOMS OF THE SLOTS IN SAID NEEDLE CYLINDER AS THE NEEDLES ARE LOWERED BY SAID STITCH CAM MEANS. 